Clock



July 9, 1946. F. Q, RAST 2,403,552

CLOCK Filed Jan. 1, 1943 6 Sheets-Sheet lv PIC-3.1.. 75

. ATTORNEY July 3%46. F. Q. RAST 24%,552

CLOCK Filed Jan. 1, 1945 6 Sheets-Sheet 3 A TTORNE Y F. C RAST July 9, 1946.

CLOCK Filed Jan. 1, 1945 6 Sheets-Sheet 5 A TTORNE Y Patented July 9, 1946 UNITED STATES PATENT OFFICE CLOCK Application January 1, 1943, Serial No. 471,037

16 Claims.

My invention relates to time keeping apparatus and more particularly toclocks and clock systems; for example, a clock system wherein one or more secondary clocks which are operated during normal operating periods at their regular time rates, are periodically regulated to correct, if necessary, their respective time settings in accordance with a selected standard time setting such, for example, as a master clock continuously oper ated at the correct time rate.

An object of the invention is to provide apparatus of the above type which is of improved construction and arrangement of parts, and one which is simple in its construction and which is reliable and effective in its operation.

In accordance with one aspect of the present invention, I provide apparatus of the above type comprising a time indicating element such as a minutes indicating member; a driving motor, such for example as a synchronous motor operated at a regular time rate from a commercial alternating current power line; and a motion-transmitting mechanism connecting the motor with the minutes member. Ihe apparatus also comprises a control means which causes the motor to drive the minutes member through the motion transmitting mechanism at its normal or regular rate during normal operating periods of fixed and relatively long durations, for example, from the beginning of each hour to the fifty-ninth minute, and which also causes the motor to drive the minutes member through the mechanism at a greatly accelerated rate during a. synchronizing period occurring between successive normal operating periods, and until the minutes member occupies a preselected time position, for example, the zero or sixtieth minute position which is the position the member should occupy at the beginning of the next normal operating period. The control means operates to stop the minutes member upon reaching this preselected time position, and releases the minutes member at the beginning of the next normal operating period, so that the setting of the minutes member will be correct at the beginning of each normal operating period.

A further object of my invention is to provide a new and improved clock for use in systems of the type referred to above, which clock comprises a novel means for periodically correcting the time setting thereof in accordance with a selected standard time setting.

A still further object is to provide a clock of the above type including new and improved motion transmitting mechanism which is controlled by a signal responsive means to operate the time indicating member from a driving motor at the regular time rate during normal operating periods and to operate the time indicating memher from the same motor at a greatly accelerated time rate during synchronizing periods.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 is a fragmentar vertical section showing one preferred form of secondary clock constructed in accordance with the present invention, the plane of the section being indicated by the line of Fig. 2, and the View showing the relative positions of the parts at the end of a synchronizing period;

Fig. 2 is a fragmentary end elevation of the clock shown in Fig. 1;

Fig. 3 is an enlarged fragmentary vertical section taken on the line 3-3 of Fig. 1;

Fig. 4 is an enlarged fragmentary plan section taken on the line 44 of Fig. 1.

Fig. 5 is a fragmentary sectional view in the same plane as Fig. 1 and showing the relation of the parts at the beginning of a synchronizing period;

Fig. 6 is a view like Fig. 5 and showing the relation of the parts during a normal operating period.

Fig. '7 is a wiring diagram illustrating how a plurality of secondary clocks like the one of Figs. 1 to 6, inclusive, may be connected for operation by a source of alternating current and how the operation of the secondary clocks may be controlled by a master clock;

Fig. 8 is a fragmentary sectional view like Fig. 1

and showing a modified form of secondary clock constructed in accordance with the present invention;

Fig. 91s a fragmentary end elevation like Fig. 2 and showing the same clock as Fig. 8;

Fig. 10 is a fragmentary vertical section taken on the line l(l-I0 of Fig. 8;

Fig. 11 is an enlarged fragmentary plan section on the line I I--l I of Fig. 8;

Fig. 12 is a wiring diagram showing an alternative way of controlling the operation of a plurality'of secondary clocks by a master clock;

Fig. 13 is a fragmentary sectional view like Figs. 1 and 8 and illustrating another modified form of secondary clock constructed in accordance with the present invention;

Fig. 14 is a fragmentary end view like Figs. 2 and 9 and illustrating the modification of Fig. 13;

Fig. 15 is an enlarged fragmentary plan section taken on the line [5-15 of Fig. 13;

Fig. 16 is a fragmentary detail sectional view showing more clearly the relationship of certain of the parts shown in Figs. 13, 14, and 15; and

Fig. 17 is a wiring diagram illustrating how a plurality of secondary clocks like the one shown in Figs. 13 to 16, inclusive, may be controlled by a master clock.

Referring now in detail to the construction illustrated and first to Figs. 1 to 6 inclusive, the reference numeral ill indicates, in itsenti-rety. one preferred form of secondary clock'con structed in accordance with the present invention. The clock I comprises the customary face plate ll, back support plate [2 and an intermediate support plate I 3 suitably secured together in fixed parallel relation by the usual pillars M. A self-starting synchronous motor I is supported by the back plate i2 and is driven at a substantially uniform time rate from the available alternating current light and power line. The synchronous motor includes a shaft l8" extending through an opening in the back plate and to the outer end of the shaft I6 is flxeda small driving pinion or gear IT.

The motor I5 drives a seconds arbor or shaft 20 by means of' thegear i1 meshing with a large spur gear 21 which is fixed to a collar 22 keyed t0 the shaft 20. The gears I1 and 2| are of such a size with respect to the speed of the motor shaft l6, that they drivethe seconds shaft 20 at the normal or regular time rate of one revolution per minute. The usual seconds hand 24 is fixed to the outerend of the shaft 20' (see Fig. 3). The seconds shaft is rotatably supported at its inner end by the back support plate l2 and is also rotatably supported by a minutes sleeve 25 journaled on said shaft and in turn supported for rotary movement about its axis and the axis'of the shaft 2il,by theintermediate support .plate l3 and by the hoursleeve 26, the latter being in turn supported by the face plate H: The minutes hand 21 is fixed to the outer end of the sleeve 25 and the hour hand 28to the outer end of the sleeve 26. The hours sleeve 26 is driven from the minutes sleeve through the conventional gear train composed of gears 29, 30, 3| and 32.

In accordancewith the present invention, I provide a planetary gear system for driving the minutes sleeve 25 during normal operating periods at the regular time rate with respect to the seconds shaft 20. The gear system comprises a planet arm 34 fixed to the collar 22 and thereby rotating about the axis of the seconds shaft at the same rate as said shaft. The planet arm 34 carries at its outer end a planet pinion 35 rotatably mounted upon a sleeve 36 which is in turn journalled on a'stud 31 fixed to the arm 34. The planetary gear system also comprises a pair of sun gears 38 and 39, respectively, which are mounted for rotation about the same axis as'the arm 34 and are both in mesh with the planet pinion. The sun gear 38 is fixed to the inner end of the minutes sleeve 25 and the other sun gear 39 is fixed to one end of a sleeve 40 rotatably mounted on the minutes sleeve 25. As will appear presently, the sun gear 39 is held stationary during normal The sun gears 38 and have the same pitch diameter and the number of teeth on the sun operating periods.

4 gear 38 is so proportioned to the number of teeth on the gear 39 that with the sun gear 39 held stationary and the planet arm 34 rotated for one complete revolution, the sun gear 38 and the minutes sleeve 25 will be advanced onesixtieth of a revolution. In the construction shown, the normally stationary sun gear 39 is provided with fifty-nine teeth and the sun gear 38-which is fixed to the minutes sleeve is provided with sixty teeth. Thus, for each rotation of the planet arm the sun gear 38 is advanced one tooth, or one sixtieth of a revolution. It will be of interest to note that during normal operating periods, the rate and direction of rotation of the pinion about its own axis are controlled by-th'e stationary sun gear 39 and by the rate and direction of rotation of the planet arm.

Fixed to the end of the sleeve to which is oppositethe sun gear 39, is a relatively large diameter circular disk 42 having teeth 43 cut on its outer periphery. During. normal operating periods a tooth-like projection Mon the outer end of an arm 45 of a lever 46 engages between two of the teeth 43 on the periphery of the disk 42 and thereby holds the disk 42, sleeve and sun gear 39 against rotation. The lever 46 is rotatably supported by a fulcrum shaft 41 which is in turn supported by the plates I2 and I3, and the projection 44 i held in looking engagement with the disk 42 by a tension spring 48 connected at one end to the lower end of the arm and its other end to the lower end of an arm 49 of an operating lever 50 also journalled on the shaft 41.

Summarizin the foregoing, it is noted that with the synchronous motor operated from the available commercial alternating current supply at its designed regulartime'rate, the seconds shaft 20 will be rotated at the rate of one revolution per minute; and, with the fifty-nine tooth sun gear 39 held stationary, the minutes sleeve 25 will berotated at the rate of one sixtieth of a revolution per minute through the planetary gear system, and the hour sleeve 26 will be driven from the minutes sleeve at the regular time rate through the train of reduction gears 29, 30, 3|, and 32, respectively. Ordinarily, the secondary clock l0 operates atthe correct time rate due to the controlled frequency of the commercial alternating 'current supply. As is well known, however, it is necessary to provide for periodically correcting the time settings of secondary clocks, because of occasional stoppage of the current supply or due to possible excess friction in the motion transmitting mechanism of one or more of the secondary clocks, or due to other causes well known to thoseskilled in this art.

According to this invention, provision is made for operating the secondary clock at the above described regular rate during each normal operating period which, in the embodiment disclosed, extends for the greater part of each hour; for example,- from the beginning ofeach hour until fifty-nine minutes past the hour. Also, provision is made for operating the clock at a greatly accelerated rate during synchronizing periods of relatively short duration, for the purpose of correcting for any loss in time. The synchronizing periods occur between successive normal operating periods and in the example disclosed the synchronizing period is the one minute interval between the fifty-ninth minute and the sixtieth minute or zero time position. Theclock starts operating at the fast rate at the beginning of the sixtieth minute and continues until the minutes and seconds indicating members reach a preselected position indicating the end of the sixtieth minute or the beginning of the next hour. At this point the minutes and seconds members are stopped and held stationary. At the beginning of the next hour the two time indicating members are released by a time signal from a master clock, thus starting the secondary clock off at the correct time.

In the construction shown in Figs. 1 to 6, in-- elusive, the minutes sleeve 25 and hand 21 of the secondary clock [5 operate at a greatly accelerated rate during synchronizing periods due to the releasing of the fifty-nine tooth sun gear 39 and by controlling the rotation of the planet pinion 35 about its rotary axis. The sun gear 39 is released by moving the lever arm 45 clockwise. to disengage the tooth-like projection 44 from the periphery of the disk 42 in a manner which will be presently described. The planet pinion 35 is controlled in its rotation about its rotary axis during synchronizing periods due to its frictional driving connection with a relatively large gear 55 which meshes with a second and relatively small gear 55 coaxially mounted with the sun gears 38 and 39 and held stationary during each synchronizing period.

The gear 55 is fixed to the sleeve 36 and is frictionally connected to the side of the pinion 35 by a spider-like spring member 5! engaging the side of the pinion and urging the latter toward the gear 55, and by a disk of suitable friction material 58 positioned between the pinion and gear to assure frictional engagement of the parts. The gear 55 which is held stationary during synchronizing periods is fixed to a sleeve 50 journaled on the outer cylindrical surfaces of the sleeve 49. A circular disk 6| of substantially the same diameter as the disk 42 is fixed to the sleeve 60 and is also provided on its periphery with teeth 62 which are adapted to be engaged and held stationary during synchronizing periods by a tooth-like projection 63 carried on the outer end of a second arm 64 of the lever 46.

The lever 46 is rocked counterclockwise, in a manner which will be presently explained, at the beginning of a normal operating period to effect locking engagement of the projection 44 and disk 42 and to effect disengagement of the projection 63 and disk 5!, and the lever 45 is rocked clockwise at the beginning of a synchronizing period to effect disengagement of the projection 44 and disk 42 and engagement of the projection 63 and disk 6!. Thus, during normal operating periods, the sun gear 39 is held against rotation and the gear 56 freely rotates with the pinion 35 under the control of the stationary sun gear; and, during synchronizing periods, the gear 56 is held against rotation to control rotation of the pinion about its axis and the sun gear 39 is permitted to freely rotate.

In the construction shown, the planet pinion 35 has thirty-six teeth. The gear 55 which is frictionally connected with the planet pinion has sixty teeth, and the gear 56 which meshes with the gear 55 and is held stationary during synchronizing periods, has thirty-six teeth. Thus, during synchronizing periods with the arm 34 rotated at the speed of the second shaft and with the sun gear 39 released, for each revolution of the arm 34, thirty-six teeth of the gear 55 will mesh with the gear 56. Consequently, the gear 55 is rotated of a revolution in a clockwise direction; and, as the gear 55 and pinion 35 are frictionally connected, the pinion 35 is also rotated of a revolution. of a revolution of the thirty-six tooth pinion 35 is equivalent to 21.6 teeth on such pinion. Therefore, for each revolution of the arm 34 the sun gear 38 is rotated an amount equal to 21.6 teeth in a counterclockwise direction; but, as the planet arm has been rotated clockwise one complete revolution, the resultant movement of the sixty tooth sun gear 38 will be sixty teeth clockwise minus 21.6 teeth counterclockwise or 38.4 teeth clockwise. This equals of a revolution for each revolution of the planet arm. As the sun gear 38 only rotates one tooth or of a revolution for each revolution of the planet arm during normal operating periods, it follows that the sun gear 35 will be driven 38.4 times as fast during synchronizing periods. This greatly accelerated rate of rotation during the one minute synchronizing period makes possible the maximum advancement of 38.4 minutes of the minute sleeve 25. This is considered ample for any ordinary condition that might arise. If a greater time correction is required, it can be effected during succeeding synchronizing periods. It will be appreciated, of course, that a greater or lesser amount of correction in a given synchronizing period can be easily provided by varying the relative sizes of the gears 55 and 55.

The lever 46 is moved in directions to effect locking and releasing of the two disks 42 and 6| due to the operative engagement of a pin 56 on the downwardly extending arm-49 of the operating lever 55, with a third arm 61 on the lever it. The operating lever 53 also includes an upstanding arm 68 having a vertical slot 69 formed there in and receiving a pin 10 carried by the lower end of a lever arm 'H. The arm H is secured intermediate its ends by a pin 12 to the armature 13 of a solenoid T4 and the upper end of the arm "H is pivoted to a pin 15 on a fixed supporting element 16 carried by the solenoid 14. As will presently appear, the solenoid 74 is energized by the flow of direct current thereto under the control of a master clock, at the beginning of each synchronizing period and is deenergized under the control of such master clock at the end of the synchronizing period. When the solenoid is energized, at the beginning of each synchronizing period, the armature 13 moves to the right as viewed in Fig. 1 and moves with it the arm H which in turn moves the operating lever 58 clockwise about the fulcrum shaft 41 to effect operative engagement of the pin 66 and arm 6'! and thereby rock the lever 46 clockwise to disengage the disk 42 and engage the disk 5! in the manner previously explained. When the solenoid is deenergized at the end of the synchronizing period, a tension spring 1'! connected at one end to the lower end of arm 49 and at its other end to a fixed stud 78, moves the lever 5!] counterclockwise and the armature 13 to the left, as viewed in Fig. 1 and thus permits the spring 48 to move the lever 46 counterclockwise to lock the disk 42 and disengage the disk 6|.

As stated above, I also provide a means which acts during synchronizing periods to stop the minutes sleeve When it reaches a preselected time position corresponding to the beginning of the next normal operating period and for holding the sleeve in this position until the beginning of the next succeeding normal operating period when it is released so that it can operate at its regular or normal time rate as before. As stated, this preselected time position is preferably the zero or sixtieth minute position. In the construction shown, this stop means comprises a relatively largecircular disk 88 which is. fixed to a sleeve 81 in turn fixed to the minutes sleeve.25 so that. it will rotate with.the minutessleeve, and the,

disk 88 isprovided on its periphery with a single notch 82 adapted to be engaged. by a .tooth-like projection 83 one. lever arm 84 when the disk .88 reachesa'position correspondingto the position.

The clockwise movement of the'pin 56 permits the .1

lever arm 84 also to be moved clockwise by a tension spring 85 connecting the ends of arm 49- and arm, and thereby to effect engagement of the projection 83 with the periphery of the disk 88. Figure 6 shows the-pin 58 engaging, the underside of the lever arm 84 and holding the projection 83 out of engagement with the disk 88,

which is the position occupied during normal,

operating periods. Figure shows the position of the parts during a synchronizing period when the arm 84 has been released so that it is in engagement with the rim of the disk 88-and before it has entered the notch 82 to stop the disk 88 and the minutes sleeve 25. Figure 1 shows the projection 83 in the notch 82 which isthe position of the parts when. the minutes sleeve 25 and disk 88 are in the preselected sixty minute position.

The aforementioned stop meansalso prefer ably, includes a means for stopping the seconds shaft 28, after the minutes sleeve has been stopped in the manner just described, at the zero or sixty;

second position of the seconds hand, so that the seconds hand as well as the minutes hand will start off at the correct time setting at the beginning of the next normal operating period. To

this end, the lever arm 84 is rigidly connected by i an integral plate 86 with an arm 81 carrying a pin 88 which fits within a horizontal slot 89 in an arm 98 also fulcrumed on the shaft 41. A' tension spring 9i connecting upstanding arms 92.-and,93 on the lever arms 88 and 81, respectively, constantly urges the arms 92 and 93 in a direction where the pin 88 normally engages the upper edge The arm 98 is provided with a. downwardly extending tooth-like projection 94 which when theprojection B3 enters'the notch 82 of the slot 89.

is moved into the path of the upper-end of.the planet arm 34 and will stop the same and the seconds shaft 28, at the zero or sixty second position, which is the position of the parts just described in l, 2, 3 and 4. The construction is such that whenthe projection 83.is down and in engagement with the rim of thedisk and before it enters the notch 82 like inFig. 5, the projection 94 is outof the path of the planet arm 34 so that the latter is free-to rotate until the projection 83 enters the notch 82 to hold the minutes member 25 at the sixtyminute position.

In Figure 7 of the drawings-there is shown a wiring diagram which illustrates one preferred.

manner of supplying a commercial alternating current to the-motors I5 ofa plurality of secondary clocks like the clock ;I 8 of Figures 1 to 6, inclusive,

howthe flow of adirect current;to the solenoids ing periods.

8. 74 of the=clocks I8 may be controlled by a master clock. operating at the correct time rate, so as to determineithe. time of beginning. and. ending of the normal operating periods and the synchroniz- The contacts 95 and 96 are apart of the master clock :of .any suitable construction known to those skilled in the. clock art, and are operated so that the contacts 95 open and the contacts 95 close at the end of each synchronizing period, which is also the beginning of the succeeding normal operating period, and so that the contacts-95-close and the contacts SGIopenat the endoi each normal operatingperiodwhich is also the beginning of the succeeding synchronizing period. As statedpreviously, in. the embodiment disclosed. the normal operating periods areselected to begin on the hour-and continue .until fifty-nineminutes past thehour, and the synchronizing periods begin at fifty-nine minutes :past theihour. andend on the hour or at each sixty minute or zero position of the clock I8. Thus, the contacts 95 will be opened and the contacts 96 .closed by the master clock at the beginningof each hour and the contacts 95 will be closed and the contacts 96 opened at fifty-nine minutes past each. hour.

In the diagram, 91 indicates a suitable transformerv having its primary connected to the usual commercial alternating currentpower and light .line indicated by the terminals 98 and 99. At the from the motors I5, through condensers I86, and.

wires I81, I88 and I89, back to the secondary I88.

The impedance of the coils of the solenoids I4. is high enough so that the A. C. current flow just described will not effect the armatures ofv these solenoids. As the contacts 95are open during the fifty-nine minute normal operating periods, current will not flow-from the secondary I I8.

At the beginning of. and during each synchronizing period with the contacts 95 closed and the contacts 69'open, and A. C. current will flow as before fromone side of-the secondary. I88 and through the wire I DI and wire I 82, but, as the contacts are open, the A. C. current will flow through the-wire III and condenser ll2'instead, andtwill then flow as before through the wires I84 and I85 to the ,motors I5 and back through the wires I81, I88, and I89 to the otherside of the secondary I88. Withthe'contacts closed, the two input terminals lI3and I I4 of-a conventional full-wave. dry-plate rectifier Il5 are connected acrossthesecondary. I IU-by the wire IIG andby the Wire I I1 and contacts 95. A DC. current will then flow. from one output terminal II8 oi the rectifier through a wire I I9,'wire I84, wires I85 connected in parallel to the coils of the solenoids 74; and the D. C. current will flow from the solenoids 14 through the wires I81, wires I88 and I89, secondary I88, wire I8I, and wire I28, to the other output terminal I2I of the rectifier II5. From theabove it is apparent that I have provided a simple and novel two wire system for operating one or. more secondary clocks I8 from the customary outlet of the usual lighting current.

The D. C. current for energizing the solenoids is superimposedon the A; C. current operating the secondary clock motors. The condenser I I2 and wire I I I provide-a pathforithe A: C. current without shorting therectifier .I I5 during synchronizing.

9 periods, and the condensers I06 prevent the flow of the D. C. current through the motors [5.

In Figs. 8 to 11, inclusive, I have shown a modified form of secondary clock Illa constructed in accordance with the present invention. The clock Ilia is similar in me my respects to the clock In disclosed in Figs. 1 to 6, inclusive. As will presently appear, the principal difference between the construction of clocks Illa and I is in the provision for controlling the operation of the planet pinion during synchronizing periods to drive the minute sleeve at the greatly accelerated rate.

Like the previous modification, the clock loa comprises a faceplate Ila, intermediate support plate Ilia, and back plate I20. suitably secured together in fixed spaced relation, and a synchronous motor [a carried by the back plate Ma and driving through spur gears Ila and Ma, and sleeve 22a, a seconds arbor or shaft a. The inner end of the seconds shaft is journaled in the back plate 12a and is supported by a minutes sleeve 25a journaled on the outer surface of the shaft 20a and by an hours sleeve 26a journaled on the minutes sleeve 25a and in turn rotatably supported within an opening in the face plate Ha. The intermediate portions of the minutes sleeve 25c are journaled within the bore of a spacing collar *5 fixed within an opening in the intermediate support plate 13a.

Also, like the previous modification, a planet arm 343a is fixed to the collar 22a and gear 2m and rotates therewith at the speed of the seconds shaft 28a. The planet arm carries on its outer end, a planet pinion a rotatably mounted upon a fixed stud 31a. and. meshing with two sun gears 38a and 39a having the same pitch diameters and also coaxially mounted for rotation about the axis of the seconds shaft 2M. As before, the sun gear 38a is provided with sixty teeth and is fixed to the inner end of the minutes sleeve 25a and the sun gea- 39a is provided with fifty-nine teeth and is fixed to the inner end of a sleeve 453a journaled on the minutes sleeve 25a. .Secured to the other end of the sleeve 40a is a large disk 42a having teeth 43a formed on its periphery and adapted to "be engaged and held stationary by a locking projection Mo on the lower end of an arm 45a of a lever Eta rotatably mounted upon a fulcrum shaft 41a which is in turn supported by the plates {2a and I3a.

Fixed to the minutes sleeve 2541 through a collar 85a is a disk B Ja having a single notch 82a in its outer periphery adapted to be engaged by a tooth like projection 83g on the outer end of a lever arm 84a also rotatably supported by the fulcrum shaft 470.. As in the previous modification, the notch 82a is so located with respect to the tooth-like projection 83a that when the latter enters the notch the minutes sleeve 25a is in the zero or sixty minute position, which is the position the sleeve should occupy at the beginning of each normal operating period.

Fixed to the lever arm 8 5a by an integral plate 86a is a second lever arm 81a journaled on the shaft ilo. and having a pin-and-slot connection with a lever Silo also fulcrumed on said shaft Ma and having a stop projection Me which, when the arms 84a. 81a and 96a are rocked clockwise and the projection 83a has entered the notch 82a, is in the path of the planet arm 34a and stops the latter and seconds shaft Zfia at the zero or sixty second position.

The lever arm 45a of lever 46a and the arm 84a are adapted to be operated by an operating lever 50a, including an arm 49a having a pin 66a extending from both sides thereof and operable when the arm 49a is moved clockwise to engage a second arm 61a on the lever 46a and to move the arm 45a clockwise against the force of a spring 480i for the purpose of disengaging the locking projection 44a from the teeth 53a of disk 42a; and the pin 66a being also operable when the lever 50a is moved counterclockwise to engage the underside of lever arm 84a and move the latter counterclockwise against the force of a spring 850: to disengage the projection 83a from the notch 82a.

As in the previous modification, the operating lever 50a includes an upward extending arm 68a having a vertical slot 69a formed therein and receiving a pin 16a carried by the lower end of an arm Ha which is pivoted at its upper end to a fixed pivot pin 15a and is connected intermediate its ends to the armature 73a of a solenoid Me.

As before, the solenoid 14a is energized at the beginning of a synchronizing period and is deenergized at the end of such period. When the solenoid is energized, the armature 13a is moved to the right as viewed in Fig. 8 thereby moving the operating lever 58a clockwise to effect the releasing of the disk 42a and minutes sleeve 25a and to permit the spring 85a to move the arm 84a clockwise so that the projection 83a engages the rim of the disk a and fits within the notch 82a when the disk 80a occupies the zero or sixty minute position. Also, when the solenoid is deenergized the tension spring Tia moves the operating arm 49o counterclockwise to effect operative engagement of the pin 56a with the arm 84a to release the disk 80a and to permit the spring 48a to move the arm 45a counterclockwise to engage and thereby lock the disk 42a against rotation.

At the end of synchronizing periodse and during normal operating periods, when the solenoid is deenergized and the disk 42a and fifty-nine tooth sun gear 39a is thereby locked, movement of the planet arm about its axis at the speed of the seconds shaft results in advancing the sixty tooth sun gear 38a and minutes sleeve 25a at the rate of one tooth or /60 of a revolution for each revolution of the planet arm.

According to this modified form of the invention, during synchronizing periods when the solenoid is energized to release the sun gear 39a, the sun gear 380: and minutes sleeve 25a are advanced at the same speed as the seconds shaft due to a frictional connection between the planet pinion and the fixed stud on which it rotates. This frictional connection is provided by means of a spider-like spring element 30 engaging the side of the planet pinion 35a and forcing the same against a disk of friction material l3! located between the pinion and the side of the arm 340.. This frictional connection offers a constant resistance to the rotation of the pinion about its axis; but such resistance is not enough to interfere with the normal rotation of the pinion, under the control of the stationary sun gear and the rotating planet arm, during normal operating periods. However, when the sun gear is released in the manner previously explained, the frictional connection is enough to hold the pinion against rotation about its axis; and, as a, consequence, the arm 34a will drive the sun gear 38a through the stationary pinion 35a, at the same speed as the arm 34a. Thus, the rotation of the planet pinion is controlled by the frictional concase may be.

Figs. 1 to 6, inclusive.

"1 1 nection during synchronizing periods so as to effeet a one-to-one driving connectionbetween the arm 34a and sleeve 25a in the manner just described. This frictional connection takes the place of the gears 55 and 56 and sleeve 50 and disk 6| of the previously'described. modification.

In Fig. 12 of the drawings, I have shown a diagram illustrating an alternative way of operating one or more secondary clocks of the type shown in either of the previously described mod iflcations, and in controlling the operation of the. clocks in accordance with the timed operation of a master clock. In the diagram, the reference character I33 indicates the primary or a I transformer I34 which may be connected to the usual alternating current supply.

The contacts I43 are a part of a master clock of any suitable construction and are intended to be closed at fifty-nine minutes past each hour to initiate the synchronizing period and to be opened at the sixty minute or zero position to end the synchronizing period and initiate the next normal operating period. When the contacts I43 are closed, current will flow from the secondary I35 through wire I36 and wire I44 to the input side of a half-Wave dry-plate rectifier I45 of suitable construction, and from the output side of the rectifier through wire I46, contacts I43, wire I41, and wires I48 connected in parallel to the coils of the solenoids I4 or 14a, as the The return sides of the solenoids are connected by the wires I39, wire I40, wire ML and wire I42 to the other side of the secondary I35. As will be apparent to those skilled in this art, current flowing from the rectifier I45 is di rect current, and flows as a series of impulses or waves. A condenser I49 in a wire I50 connecting the wires I42 and I4! is provided for smoothingout the D. C. current flow and thereby rendering the same more constant. This construction and operation of a half-wave rectifier combined with a condenser is of course well known to those skilled in this art and requires no further explanation.

In the modified form of secondary clock IDb shown in Figs. 13, 14, and 16, and in the circuit diagram in Fig. 17, I have disclosed an alternative construction of the operating lever 50b and an alternative means for moving the oper- "in the two previously described modifications.

Other than the structure of the operating lever 50b and the structure and operation of the mechanism, to be described, for moving the lever 50b in response to the two signals, the structure and I operation of each of the other elements of the clock 10?) is identically the same as the corresponding parts in the modification shown in Consequently, I will not repeat herein the description of these other elements of the clock Illb except as is required to understand the construction and operation of the elements which have been modifiedv The operating lever 50b comprises the arm 4% the solenoid 74b is energized, and is moved to 12 carrying the. pin 6% which coasts with the arms Ill?) and 84b to effect locking and unlocking of the disks EI b and' 42b and to effect engagement and disengagement of the projection 8321 with the disk 83b all in the same manner and for the same purpose as corresponding parts of the previously described modification of Figs. 1 to 6, inclusive. In addition to the arm 49b, the lever 50b also includes an arm I15 having a longitudinal extending slot I75 formed therein and receiving the outer end of a stud or pin I'I'I carried by the lower end of a lever IIll (see also Fig. 16). The lever H3 is pivoted at its upper end on a fixed fulcrum stud Ill; carried by the intermediate support plate I 3%) and is provided interme its end; with an outwardly projecting follower pin it operable to engage and be moved by the multiple lobe cam Isl. The cam [BI is fixed to a slee [S2 journaled on the fulcrum shaft 41b and the cam comprises a plurality of similar lobes I333 which are equally spaced circumferentially from one another to provide similar recesses I 24 there- ,between and are formed on their respective peaks with similar dwell portions I05. A ratchet wheel I86 is also fixed to the sleeve I82 and is open ated by a pawl I8? pivoted on the pin 10b which carried by the lower end of lever arm 'IIb. Like in the previous modifications, the arm III; is pivoted at its upper end to a fixed pin 75?) and is connected intermediate its ends to a pin 72b carried by the outer end of the armature 13 of the solenoid 141). A tension spring I90 connects the lower end of the arm IIb and a fixed stud 'ISI carried by the plate I3?) and functions when the solenoid 14b is deenergized to move the arm lib and pawl I81 to the left as shown in Fig. 13 for the purpose of indexing the ratchet wheel I85 and cam IIiI in a countercloclnvise direction. A non-return pawl I 32 is pivoted on the stud Ill) and is held in engagement with the ratchet wheel I86 by a tension spring I93 connecting the pawl I92 and stud IQI As will be apparent from the foregoing, the pawl It"! is 'moved to the right viewed in Fig. 13 by the arm lib and armature I321 when the left by the spring I01} when the solenoid is deenergized. The length of movement of the pawl I8! is such as to advance the ratchet wheel counterclockwise one tooth each time the solenoid is deenergized. In the construction shown the ratchet is provided with twenty-four teeth and the cam I 6| with twelve lobes I 53. Thus. each time the ratchet wheel I85 is advanced one tooth the cam I8I is moved counterclockwise one half the distance between radial center lines oi adjacent lobes I83. The cam is so positioned with respect to the ratchet that at the end of each stroke in an advancing direction of the pawl I37, the pin I will be midway of either dwell portion I or midway of a recess portion I84. When the cam IilI moves the pin I80 from u recess I84 to a high dwell point I85 the lever I10 is moved clockwise and thereby also moving through the pin III the operating lever 56?) in a clockwise direction. When the cam I80 moves so that the pin ISI will occupy a recess I84, the arm IE8 is moved counterclockwise under the control of the cam. The force for moving the arm counterclockwise is supplied by the spring lb and acts through the operating lever 5th and pin Ill, as will be apparent.

As set forth in the description of Figs. 1 to 6. inclusive, clockwise movement of the operating lever 50?) results in the pin 66b moving the lever 46b clockwise to release the disk 42b and lock the disk Bib, and in permitting the spring 8512 to move the lever 84b into engagement with the disk 80b so as to stop the latter in the sixty minute position when the projection 83b enters the notch 82?), and to move the arm 9% down into the path of the planet arm 3417 when the projection 83b enters the notch 82?), for the purpose of stopping the seconds shaft in the sixty second position. Also, counterclockwise movement of the lever 50b results in the pin 60b moving the arms 84b and Bill) to release the disk Blib and the planet arm 34b, and results in the spring Mil) moving the lever 43b counterclockwise to lock the disk 42b and release the disk filb.

According to the modified construction of Figs. 13, 14, 15, and 16, the pin I 35) occupies a recess I84 during normal operating periods and engages a high dwell point I85 during synchronizing periods. In Fig. 17, I have shown a wiring diagram illustrating how the motors I51) of the clocks Iilb are operated by an A. C. current from the usual power and light line and how the operation of the clocks is controlled by a master clock operating at the correct time rate. In the diagram, the contacts 20%), 20L 2232, and 233 are a part of a master clock of any well known construction and are operated so that the contacts 200 are closed at the sixty minute (60') position of each hour and are opened at fifty-eight minutes and forty seconds (58' 40") past each hour, the contacts 20I are closed at fifty-eight minutes and forty seconds (58 40") past each hour and are opened at the sixty minute (60') position, the contacts 202 are opened at each fifty-eight second (58) position and are closed at each sixty secon'l (60") position, and so that the contacts 2% are closed at each fifty-eight second (58) position and are opened at each sixty second (60") position.

The primary 204 of the transformer 205 is adapted to be connected to any convenient source of alternating current. When the contacts 2553 are closed, A. C. current will flow from a midpoint 206 of the secondary 201 through a wire 208, the contacts 200, wire 209 and the wires 2m connected in parallel, to the motors b of the secondary clock; and will flow from the motors through wires ZI I, wire 2I2, and wire 213, back to the secondary 201. Thus the motors I517 will be operated by A. C. current through the closed contacts 200 from the beginning of each normal operating period until fifty-eight minutes and forty seconds past each hour when the contacts 200 open. As the contacts 202 remain closed from the beginning of each minute until fiftyeight seconds past each minute, A. C. current will also flow to the motors during the fifty-eight seconds beginning with the fifty-ninth minute. The path of the current flow will be from the secondary 201 through the wire 2%, wire 2M, closed contacts 202 and wire 2I5, to the wire 209, and from there through the motors IEb back to the secondary 201, as before. A half-wave rectifier 2I6 is connected to the secondary 201 by a wire 2I1, and when the contacts I and 203 are both closed, a D. C. current will flow from the output side of the rectifier 2I6 through a wire 2I8, contacts 20I, wire 2I9, contacts 203, wire 220, wire 209, wires 2I0, to the solenoids 14b and from the solenoids through the wires 2 I I, a wire 2I2, and wire 2I3 back to the secondary Sill. A wire 22I with a condenser 222 therein, connects the wire 2I9 and the secondary 201 for the pur- 14 pose of smoothing out or making more uniform the 1 0. current.

FrOm the foregoing, it is apparent that the solenoid 141) will be energized for a two-second duration beginning at fifty-eight minutes and fifty-eight seconds past each hour and ending at fifty-nine minutes past each hour, and will be again energized for a'two second duration beginning at fifty-nine minutes and fifty-eight seconds past each hour and ending at the zero or sixty minute position. As the contacts 252 are open, when the contacts 203 are closed which is during these two two-second intervals when the solenoids 14b are energized, no A. C. current will flow to the motors [51) during such intervals. This, however, will not materially affect the operation of the motors as the normal inertia of the moving parts will be enough to keep the mo tors in motion during these two short intervals.

In Figs. 13, 14 and 15 the parts are shown in the positions which they occupy when the solenoid 14b is being energizezd for the two second duration between fifty-nine minutes and fiftyeight seconds after each hour and the sixty minute or zero position. The armature 13b is shown retracted and the pawl I81 in its right-hand position as viewed in Fig. 13. The pin I30 on the lever I18 is shown as being in engagement with a high dwell point I85 on the cam IBI. This is the position it occupies during each synchronizing period. When the solenoid 14b is deepergized, by the opening of contacts 203, and also contacts 20I, at the sixty minute position, the spring I will move the pawl I81 to the left and index the ratchet I86 and cam I8I to permit the pin I89 to be moved into the next depressed portion I84 which also permits the arm I18 and operating lever 50b to be moved counterclockwise by the spring 111), to lock the disk 42b and release the disk Elb and to move the arms 04b and 90b counterclockwise t release the disk 8% and the planet arm 34b. The secondary clocks I0b will then operate at their normal rate until the solenoid 1 41) is again energized and then deenergized at fifty-nine minutes past the hour to index the ratchet I86 and cam IBI so as to move the arm I18 and operating level Eilb clockwise which is the position they occupy during each. synchronizing period.

While therehave been shown and described and pointed out the fundamental novel features of the invention as applied to a plurality of modifications, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art. without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. In a clock of the type wherein the minutes member is driven at its regular time rate during normal operating periods by means of a rotating planet arm and a planet pinion rotatably mounted thereon and geared to a pair of coaxially mounted sun gears one of which has a driving connection with the minutes member and the other of which is held stationary during such normal operating periods, the combination of means operable during a synchronizing period occurring between successive normal operating periods for correcting for loss of time and said means including means for releasing the other of said sungears, means for rotating said pinion .in the same direction-as during normal operating periods, but at a definitely slower rate whereby said one sun gear is rotated at a greatly accelerated rate, and means for determining the amount said minutes member is advanced during such synchronizing period.

2. Time keeping apparatus comprising a rotatable time indicating member; mechanism operating at a predetermined definite time rate materially greater. than the normal time rate for said member; aplanetary gear system connecting said mechanism and said member for rotating thelatter at the proper time rate during normal operating periods and comprising a planet arm operatively connected to saidmechanism forrotation about a .fixed axis, a planet pinion rotatably mounted on said arm and movable therewith along a prescribed orbit, and first and second sun gears mounted, respectively, to rotate about said fixed axis and geared to said pinion, said first sun gear having. a driving connection with said member, the number of teeth on said first and second sun gears being so proportioned that with said second gear held stationary, said firstgear is advanced at a rate proper to rotate said member at its normal time rate; signal means determining a synchronizing period of relatively short duration occurring at regular time intervals between successive normal operating periods; means for holding saidsecond gear stationary during normal operating periods and for releasing said second gear during synchronizing periods; means for controllingthe rotation of said planet pinion to cause said arm to drive said first sun gear at a greatly accelerated rate during synchronizing periods; and stop means operable in response to said signal means and during said synchronizing period for stopping said member upon reaching a predetermined time position and operable to release saidmember at the beginning of the next succeeding normal operating period.

3. Time keeping apparatus comprising a rotatable seconds indicating member; a rotatable minutes indicating member; mechanism for rotating said seconds member at its normal time rate; a planetary gear system connecting said mechanism and said minutes member for rotating the latter at its normal time rate during normal operating periods and comprising a planet arm operatively connected to said mechanism for rotation about a fixed axis, a planetpinion rotatably mounted on said arm and movable therewith along a prescribed orbit, and first and second sun gears mounted, respectively, to rotate about said fixed axis and geared to said pinion, said first sun gear having a driving connection with said minutes member, the number of teeth on said first and second sun gears being so proportioned that with said second gear held stationary, said first gear is advanced at a rate proper to rotate said minutes member at its normal time rate; signal means determining a synchronizing period of relatively short duration occurring at regular time intervals between successive normal operating periods; means for holding said second sun gear stationary during normal operating periods and for releasing said second gear during synchronizing periods; means for controlling the rotation of said planet pinion to cause said arm to drive said first sun gear at a greatly accelerated rate during synchronizing periods; and stop means operable in response to said signal means and during said synchronizing period for stoppingsaid minutes and seconds .members'upon reaching a predetermined time position and operable to release said minutes and seconds members at the beginning of the next succeeding normal operating period.

4. Time keeping apparatus comprising a rotatable minutes indicating member; mechanism including a planetary gear system for rotating said member at its normal time rate and comprising a planet arm rotatable about a fixed axis at the rate of one revolution per minute, a planet pinion rotatably mounted on said arm and movable therewith along a prescribed orbit, first and second sun gears rotatably mounted about said fixed axis and geared to said pinion, said first gear having a driving connection with said 'minutes member, the number of teeth on said first and second gears being so proportioned that with said second gear held stationary said first gear is advanced at a rate proper to rotate said member at its normal time rate; signal means determining a synchronizing period of relatively short duration occurring at regular time intervals between successive normal operating periods; means for holding said second gear stationary during normal operating periods and for releasing said second gear during synchronizing periods; means for controlling the rotation of said planet pinion to cause said arm to drive said first gear at a greatly accelerated rate during synchronizing periods; and stop means operable in response to said signal means and during said synchronizing period for stopping said arm and said minutes member upon reaching a predetermined time position and operable to release said arm and said member at the beginning of the next succeeding operatin period.

5. Time keeping apparatus comprising a time indicating member; mechanism for rotating said member at the normal time rate during normal operating periodsand comprising a planet arm rotated .about a fixed axis at a definite time rate materially greater than the normal time rate for said member, a planet pinion rotatably mounted r' on said arm and movable therewith along a prescribed orbit, first and second sun gears mounted for rotation about said fixed axis and geared to said pinion, said first gear having a driving connection with said member, said second gear being held stationary during normal operating periods, the number of teeth on said first and second gears being so proportioned that the first gear is advanced by said arm and pinion during normal operating periods at a rate proper to rotate said member at its normal time rate; and means operable during a synchronizing period occurring between successive normal operating periods to correct for loss of time and to start said time indicating member off at the correct time at the beginning of the nextnormal operating period and said means comprising means for releasing said second gear, means for rotating said pinion in the same direction as during a normal operating period but at a materially slower rate, and means for stopping said time indicating member upon reaching a predetermined time position and for releasing such member at the beginning of the next normal operating period.

6. Time keeping apparatus comprising a seconds indicating member; means fo rotating said member at its normal time rate; a planet arm connected to said member and rotatable therewith about the axis of movement of said member and at the same rate; a planet pinion rotatably mounted on the outer end of said arm and movable therewith along a prescribed orbit; a rotary minutes member coaxially mounted with respect to said secondsimember; a first sun gear fixed to said minutes member and rotatable about its axis and meshing with said pinion; a second sun'gear coaxially mounted with said first gear and also meshing with said pinion and being held stationary during normal operating periods; the number of teeth on said two sun gears bearing such a relation thatwith said secondgear held stationary said first gear is rotated one sixtieth of a revolution for each revolution of said arm; and means operable during a synchronizing period, occurring between successive normal operating periods to correct for loss of time and comprising means for releasing said second sun gear and for controlling the rotation of said pinion to cause said first gear to rotate at a greatly accelerated rate, and meansfor stopping said arm and said minutes member upon reaching apredetermined time position and for releasing such arm and minutes member at the beginning of the next. succeeding normal operating period.

'7. Time keeping apparatus comprising a rotatable time indicating member; mechanism operating at a definitev time rate materially greater than the normal time rate for said member; aplanetary gear system connecting said mechanism and said, member for rotating the latter at its normal time rate during normal operating periods and comprising a planet arm operatively connected to said mechanism for rotation about a fixed axis, a planet pinion rotatably; mounted on said arm and movable therewith along a prescribed orbit, and first and second sun gears mounted, respectively, to rotate about said fixed axis and geared to said pinion, said first sun gear having a driving connection with said member, the number of teethon said first and. second sun gears beingso proportioned that with saidsecond gear held stationary, said first gear is advanced at a rate properto rotate said member at its normal time rate; a third gear mounted for rotation about said fixed axis and being of substantially less diameter than said first sun gear; gear means connecting said third gear and said planet pinion; signal means determining a synchronizing period of relatively short duration occurring at regular time intervals between successive normal operating periods; means for holding said second gear stationary during normal operating periods and for releasing said second gear during synchronizing periods; means. for holding said third gear against rotation during synchronizing periods and 'for releasing such gear to permit free rotation thereof during normal operating periods; and stop means operable in response to said signal means and during said synchronizing period for stopping said member upon reaching a predetermined time position and operable to release said member at the beginning of the next succeeding normal operating period.

8. Time keeping. apparatus comprising a rotatable time indicating member; mechanism operating at a definite time rate materially greater than the normal time rate for said member; a planetary gear system connecting said mechanism and said member for rotating the latter at its normal time rate during normal operating periods and comprising a planet arm operatively connected to said mechanism for rotation ,-ab'out a fixed axis, aplanet pinion rotatably mounted on said arm and movable therewith along a prescribed orbit, and first and second sun gears mounted, respectively, to rotate about said fixed axis and geared tosaid pinion, said first sun gear having a driving connection with said member, the number of teeth on said first and second sun gears being so proportioned that with said second gear held stationary, said first gear is advanced at a rate proper to rotate said member at its normal time rate; signal means determining a synchronizing period of relatively short duration occurring at regular time intervals between successive normal operating periods and including means for sending a first signal to initiate said synchronizing period and for sending a second signal to terminate such period; means responsive to said first signal to release said second gear to permit free rotation thereof and responsive to said second signal for locking said second gear against rotation; means for controlling rotation of said planet pinion to cause said arm to drive said first sun gear at a greatly accelerated rate during said synchronizing period; and stop means responsive to said first signal for stopping said time indicating member upon reaching a predetermined time position and responsive to said second signal for releasing said member.

9. A clock comprising a rotatable time indicating member; a motor constructed to operate at a uniform time rate; a planet arm operatively connected to said motor and supported for rotation thereby about a fixed axis and at a time rate materially faster than the normal operating rate for said member; a planet pinion rotatably mounted on said arm and movable therewith through a prescribed orbit; a pair of sun gears mounted for rotation about the same axis as said arm and geared to said pinion; one of said sun gears having a driving connection with said time indicating member and the number of teeth on said one sun gear being so proportioned to the number of teeth on the other of said sun gears that with said other gear held stationary said one gear is rotated by said arm and pinion at a rate correct to drive said member at its regular time rate; means for holding said other gear stationary during normal operating periods; and means for advancing the setting of said time indicating member comprising means for releasing said other sun gear and means for rotating said pinion about its rotary axis in the same direction as it rotates when said other gear is held stationary, but at a definitely slower rate.

10. A clock comprising a rotatable time indicating member; a motor constructed to operate at a uniform time rate; a planet arm operatively connected to said motor and supported for rotation thereby about a fixed axis and at a time rate materially faster than the normal operating rate for said member; a, planet pinion rotatably mounted on said arm and movable therewith through a prescribed orbit; a pair of sun gears mounted for rotation about the same axis as said arm and geared to said pinion; one of said sun gears having a driving connection with said time indicating member and the number of teeth on said one sun gear being so proportioned to the number of teeth on the other of said sun gears that with said other gear held stationary said one gear is rotated by said arm and pinion at a rate correct to drive said member at its regular time rate; means for holding said other gear stationary during normal operating periods; and means for changing the setting of said time indi- 19 cating member comprising means for releasing said other sun gear and means for positively rotating said pinion about its rotary axis and at a predetermined rate different from its rate of rotation while said other sun gear is held stationary.

11. A clock comprising a rotatable time indicating member; a motor constructed to operate at a uniform time rate; a planet arm operatively connected to said motor and supported for rotation thereby about a fixed axis and at a time rate materially faster than the normal operating rate for said member; a planet pinion rotatably mounted on said arm and movable therewith through a prescribed orbit; a pair of sun gears mounted for rotation about the same axis as said arm and geared to said pinion; one of said sun gears having a driving connection with said time indicating member and the number of teeth on said one sun gear being so proportioned to the number of teeth on the other of said sun gears that with said other gear held stationary said one gear is rotated by said arm and pinion at a rate correct to drive said member at its regular time rate; means for holding said other gear stationary during normal operating periods; and.v

means for advancing the setting of said time indicating member comprising an electromagnet ele-- merit operable upon a change in flow of current thereto, means responsive to the operation of said element for releasing said other sun gear and for efiecting positive rotation of said pinion about its rotary axis and in the same direction as it rotates when said other gear is held stationary but at a definite slower rate.

12. A clock comprising a rotatable time indicating member; a motor constructed to operate at a uniform time rate; a planet arm operatively connected to said motor and supported for rotation thereby about a fixed axis and at a time rate materially faster than the normal operating rate for said member; a planet pinion rotatably mounted on said arm and movable therewith through a prescribed orbit; a pair of sun gears mounted for rotation about the same axis as said arm and geared to said pinion; one of said sun gears having a driving connection with said time indicating member and the number of teeth on said one sun gear being so proportioned to the number of teeth on the other of said sun gears that with said other gear held stationary said one gear is rotated by said arm and pinion at a rate correct to drive said member at its regular time rate; means for holding said other sun gear stationary during normal operating periods; and means for changing the setting of said time indicating member comprising an electromagnetic element operable upon a change in flow of current thereto, and means responsive to the operation oi. said element for releasing said other sun gear and for effecting positive rotation of said pinion about its axis and at a predetermined rate difierent from its rate of rotation while said other sun gear is held stationary.

13. Time keeping apparatus comprising a rotatable time indicating member; mechanism operating at a definite time rate materially greater than the normal time rate for said member; a planetary gear system connecting said mechanism and said member for rotating the latter at its normal time rate during normal operating periods and comprising a planet arm operatively connected to said mechanism for rotation about a fixed axis, a planet pinion rotatably mounted on said arm and movable therewith along a prescribed orbit, and first and second sun gears mounted, respectively, to rotate about said fixed axis and geared to said pinion, said first sun gear having a driving connection with said member, the number of teeth on said first and second sun gears being so proportioned that with said second gear held stationary, said first gear is advanced at a rate proper to rotate said member at its normal time rate; a third gear mounted for rotation about said fixed axis and being of substantially less diameter than said first sun gear; gear means connecting said third gear and said planet pinion; means for holding said second gear stationary during normal operating periods; said third gear being free to rotate during normal operating periods; and means for correcting for loss of time comprising means for releasing said second gear, means for holding said third gear against rotation, and means for stopping said time indicating member upon reaching a predetermined time position.

14. Time keeping apparatus comprising a rotatable time indicating member; mechanism operating at a definite time rate materially greater than the normal time rate for said member; a planetary gear system connecting said mechanism and said member for rotating the latter at its normal time rate during normal operating periods and comprising a planet arm operatively connected to said mechanism for rotation about fixed axis, a planet pinion rotatably mounted on said arm and movable therewith along a prescribed orbit, and first and second sun gears mounted, respectively, to rotate about said fixed axis and geared to said pinion, said first sun gear having a driving connection with said member, the number of teeth on said first and second sun gears being so proportioned that with said second gear held stationary, said first gear is advanced at a rate proper to rotate said member at its normal time rate; a third gear mounted for rotation about said fixed axis and being of substantially less diameter than said first sun gear; gear means connecting said third gear and said planet pinion; means for holding said second gear stationary during normal operating periods; said third gear being free to rotate during normal operating periods; and means for advancing the setting of said time indicating member comprising means for releasing said second gear and means for holding said third gear against rotation.

15. Time keeping apparatus comprising a driving motor constructed to operate at a uniform time rate; a time indicating member; adjustable motion transmitting mechanism connecting said driving motor and said member and operable in a first adjusted condition to effect 01 eration of said member at its normal time rate, and operable in a second adjusted condition to effect operation of said member at a greatly accelerated rate; and control means including signal means determining a synchronizing period of relatively shore duration and occurring at regular time intervals between successive normal operating periods and including means for sending a first signal to initiate each synchronizin period and for sending a second signal to terminate such period, means responsive to said first signal for adjusting said mechanism to operate in its said first adjusted position and responsive to said second signal for adjusting said mechanism to operate in its said second adjusted position, and means operated by said signal responsive means for stopping said time indicating member upon reaching a position indicating the beginning of the next normal operating period and for releasing said member at the beginning of said next normal operating period.

16. In time keeping apparatus a, driving motor; a seconds indicating member operated at its normal time rate by said motor; a minutes indicating member; motion transmitting mechanism connecting said motor and said minutes member and being constructed with two conditions of adjustment, one of which provides for driving said minutes member at its normal time rate and the other of which provides for driving the minutes member at a rate materially faster than normal; means for operating said mechanism in its said other condition of adjustment during a snychronizing period of predetermined duration and for changing said mechanism to operate in its said one condition of adjustment at the end of said synchronizing period; a first stop element movable between an inactive position and an active position where said minutes member is stopped thereby upon reaching a selected time position; a second stop element movable between an inactive position and an active position where said seconds member is stopped thereby upon reaching a selected time position; means for mow'ng said first element into its said active position at the start of the synchronizing period and for afterwards moving said second element into its said active position and concurrently with the stopping of said minutes member; and means for returning both said elements to their inactive positions at the end of said synchronizing period.

FREDERICK Q. RAST. 

